1. Field of the Invention
The present invention relates to a camera such as a digital camera, a video camera and a silver-halide camera, an aperture controlling method, an aperture controlling apparatus, a lens controlling method, a lens controlling apparatus, an edging amount controlling method and an edging amount controlling apparatus which are applied to an optical system of the camera.
2. Description of the Related Art
In a conventional art, an operatable range of a lens is restricted with regard to a diaphragm for a camera, a point-blank limit, and a zoom limit, in order to secure a predetermined optical capability (e.g. an imaging capability) of the lens. Concerning the diaphragm for example, a maximum and a minimum aperture sizes are so specified as to control the diaphragm within the operatable range. Japanese Patent Application Laid-open No. 5-53170 discloses changing a diaphragm corresponding with a zoom position and correcting a variance of the diaphragm due to zooming. A diaphragm adjusting system using a solid-state imaging device illuminates an auxiliary light if a subject is too dark, and also raises outputting power by gaining an output from the imaging device (called “gain-up”), thereby gaining a signal level.
However, in an automatic exposure adjustment (AE), because noise compositions are amplified by gaining up and performing photometry if the brightness of the subject is too low, many errors occur, and photometry capability at a low brightness is poor. Similarly, with an auto focusing adjustment in which a portion having the most of high frequency compositions of a video signal is a focus position, focusing capability is lowered because the noise compositions are amplified if the output signal of the imaging signal is amplified.
Other problems concerning the conventional camera are that: the camera easily vibrates when using an electronic zoom, an image quality of a movie display for confirming a view angle is deteriorated with respect to the subject with a low brightness, observability of the movie display is poor due to a smear phenomenon which occurs in taking of the subject with extreme brightness, and so forth.